Remove faulty location.href fallback and disable --split-linked-modules by default (#3279)

* Remove faulty `location.href` fallback

* Disable `--split-linked-modules` in cli-support

Author: daxpedda

.github/workflows/main.yml

@@ -41,6 +41,8 @@ jobs:
   test_wasm_bindgen:
     name: "Run wasm-bindgen crate tests (unix)"
     runs-on: ubuntu-latest
+    env:
+      WASM_BINDGEN_SPLIT_LINKED_MODULES: 1
     steps:
     - uses: actions/checkout@v2
     - run: rustup update --no-self-update stable && rustup default stable

crates/cli-support/src/js/mod.rs

@@ -381,9 +381,7 @@ impl<'a> Context<'a> {
                 js.push_str("let script_src;\n");
                 js.push_str(
                     "\
-                    if (typeof document === 'undefined') {
-                        script_src = location.href;
-                    } else {
+                    if (typeof document !== 'undefined') {
                         script_src = new URL(document.currentScript.src, location.href).toString();
                     }\n",
                 );
@@ -720,7 +718,7 @@ impl<'a> Context<'a> {
                     stem = self.config.stem()?
                 ),
                 OutputMode::NoModules { .. } => "\
-                    if (typeof input === 'undefined') {
+                    if (typeof input === 'undefined' && script_src !== 'undefined') {
                         input = script_src.replace(/\\.js$/, '_bg.wasm');
                     }"
                 .to_string(),

crates/cli-support/src/lib.rs

@@ -121,7 +121,7 @@ impl Bindgen {
             wasm_interface_types,
             encode_into: EncodeInto::Test,
             omit_default_module_path: true,
-            split_linked_modules: true,
+            split_linked_modules: false,
         }
     }
 

crates/cli/src/bin/wasm-bindgen-test-runner/main.rs

@@ -167,6 +167,10 @@ integration test.\
         TestMode::NoModule => b.no_modules(true)?,
     };
 
+    if std::env::var("WASM_BINDGEN_SPLIT_LINKED_MODULES").is_ok() {
+        b.split_linked_modules(true);
+    }
+
     b.debug(debug)
         .input_module(module, wasm)
         .keep_debug(false)

crates/cli/tests/wasm-bindgen/main.rs

@@ -260,16 +260,14 @@ fn default_module_path_target_no_modules() {
         fs::read_to_string(out_dir.join("default_module_path_target_no_modules.js")).unwrap();
     assert!(contents.contains(
         "\
-    if (typeof document === 'undefined') {
-        script_src = location.href;
-    } else {
+    if (typeof document !== 'undefined') {
         script_src = new URL(document.currentScript.src, location.href).toString();
     }",
     ));
     assert!(contents.contains(
         "\
     async function init(input) {
-        if (typeof input === 'undefined') {
+        if (typeof input === 'undefined' && script_src !== 'undefined') {
             input = script_src.replace(/\\.js$/, '_bg.wasm');
         }",
     ));

guide/src/reference/cli.md

@@ -122,3 +122,7 @@ using a plugin. Alternatively, you can leave the syntax as is and instead
 manually configure the bundler to copy all files in `snippets/` to the output
 directory, preserving their paths relative to whichever bundled file ends up
 containing the JS shim.
+
+On the no-modules target, `link_to!` won't work if used outside of a document,
+e.g. inside a worker. This is because it's impossible to figure out what the
+URL of the linked module is without a reference point like `import.meta.url`.